The discussion of dynamic modulus of asphalt mixtures under biaxial stresses

Abstract

Asphalt pavement in service is subjected to a complicated state of stress, especially in the uphill or starting and braking sections. The normal stress and the shear stress load it together. Only uniaxial vertical load was taken into account in the testing of dynamic modulus when a pavement was designed at present. In this paper, the dynamic response tests were carried out by applying the dynamic normal and shear loads to cylindrical specimens of asphalt mixtures. The dynamic modulus under vertical loading and vertical-horizontal loading were compared to analyze the effect of the combination loading. The result indicated vertical dynamic modulus under biaxial loading was significantly lower than vertical loading, as opposed to dynamic shear modulus. It could be concluded that the properties of asphalt mixture from biaxial stresses state should be paid more attention in the design of pavement, especially in the intersection and uphill sections.